FrameBufferObject only outputting one frame to screen

Question

I have used some code from a tutorial and implemented in a personal project, but the FrameBufferObject is only displaying one frame, and then never displays anything again.

Here's the code that I use: (in glutDisplayFunc())

glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_FBO);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Render out objects, using glsl shaders with MVPs
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
glClearColor(0.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(m_Shader);
glBindTexture(GL_TEXTURE_2D, m_DiffuseTexture);
glUniform1i(uniform_fbo_texture, /*GL_TEXTURE*/0);
glEnableVertexAttribArray(attribute_v_coord_postproc);
glBindBuffer(GL_ARRAY_BUFFER, vbo_fbo_vertices);
glVertexAttribPointer(attribute_v_coord_postproc,2,GL_FLOAT,GL_FALSE,0,0);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glDisableVertexAttribArray(attribute_v_coord_postproc);
glutSwapBuffers();

All the functionality you can see above is actually abstracted to functions and classes, but this is what all of it does. m_Shader is a class that is able to convert to gluint (its ID).

Here's the constructor functionality of the FBO class:

/* Texture */
glActiveTexture(GL_TEXTURE0);
glGenTextures(1, &m_DiffuseTexture);
glBindTexture(GL_TEXTURE_2D, m_DiffuseTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, a_Width, a_Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glBindTexture(GL_TEXTURE_2D, 0);

/* Depth buffer */
glGenRenderbuffers(1, &m_DepthBuffer);
glBindRenderbuffer(GL_RENDERBUFFER, m_DepthBuffer);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, a_Width, a_Height);
glBindRenderbuffer(GL_RENDERBUFFER, 0);

/* Framebuffer to link everything together */
glGenFramebuffers(1, &m_FBO);
glBindFramebuffer(GL_FRAMEBUFFER, m_FBO);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_DiffuseTexture, 0);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, m_DepthBuffer);
// check FBO status
GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
{
    char tmps[256]; 

    switch (status)
    {
    case GL_FRAMEBUFFER_COMPLETE_EXT:
        strcpy_s(tmps, 256, "Frame buffer complete");
        return;

    case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:
        strcpy_s(tmps, 256, "Frame buffer incomplete: Attachment is NOT complete");
        return;

    case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
        strcpy_s(tmps, 256, "Frame buffer incomplete: No image is attached to FBO");
        return;

    case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
        strcpy_s(tmps, 256, "Frame buffer incomplete: Attached images have different dimensions");
        return;

    case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
        strcpy_s(tmps, 256, "Frame buffer incomplete: Color attached images have different internal formats");
        return;

    case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
        strcpy_s(tmps, 256, "Frame buffer incomplete: Draw buffer");
        return;

    case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
        strcpy_s(tmps, 256, "Frame buffer incomplete: Read buffer");
        return;

    case GL_FRAMEBUFFER_UNSUPPORTED_EXT:
        strcpy_s(tmps, 256, "Unsupported by FBO implementation");
        return;

    default:
        strcpy_s(tmps, 256, "Unknown error");
        return;
    }

    char tmps2[256];
    sprintf_s(tmps2, 256, "FBO not setup OK: '%s'", tmps);

    MessageBox(NULL, tmps2, "Error", MB_ICONSTOP);
}
glBindFramebuffer(GL_FRAMEBUFFER, 0);
GLfloat fbo_vertices[] = 
{
    -1, -1,
     1, -1,
    -1,  1,
     1,  1,
};
glGenBuffers(1, &vbo_fbo_vertices);
glBindBuffer(GL_ARRAY_BUFFER, vbo_fbo_vertices);
glBufferData(GL_ARRAY_BUFFER, sizeof(fbo_vertices), fbo_vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);

m_Shader.Add(GL_VERTEX_SHADER, "data/shaders/postProcess.vert");
m_Shader.Add(GL_FRAGMENT_SHADER, "data/shaders/postProcess.frag");
attribute_v_coord_postproc = glGetAttribLocation(m_Shader, "v_coord");  
uniform_fbo_texture = glGetUniformLocation(m_Shader, "fbo_texture");